The lack of action on this is evidence of mankind's selfishness and shortsightedness. I hope a technological solution is forthcoming, because political solutions have failed spectacularly. The oil industry has invested so much in disinformation that they may destroy our habitat forever for some temporary shareholder value.
At 1.5 degrees C, sea levels are expected to rise up to ~30 inches, which would put huge parts of New Orleans, Corpus Christie, Key west, Southern Florida, SF's south bay, and Miami underwater. See what goes underwater using this NOAA map.